First Trimester Ultrasound

First trimester ultrasound is performed in the first 3-4 months of a pregnancy.  Pregnancy ultrasounds are performed mainly using transabdominal ultrasound. For many women, especially after eight weeks gestation, sufficient information about the baby may be obtained with transabdominal ultrasound only.  However, in the early pregnancy, the developing embryo is very small (at six weeks gestation, the baby is only 5-9 mm long) and a transvaginal ultrasound may be required to get a better image of the baby.  Transvaginal ultrasound is safe and commonly performed during all stages of pregnancy, including the first trimester.  It will not harm you or your baby.   

Transabdominal ultrasound: involves scanning through your lower abdomen.  A small amount of ultrasound gel is put on the skin of the lower abdomen, with the ultrasound probe then scanning through this gel.  The gel helps improve contact between the probe and your skin.  

Transvaginal ultrasound: is an internal ultrasound.  It involves scanning with the ultrasound probe lying in the vagina.  Transvaginal ultrasound usually produces better and clearer images of the female pelvic organs including the developing pregnancy, because the ultrasound probe lies closer to these structures.

Preparation:  A full bladder is essential for this exam.  If the instructions are not followed another appointment will have to be made.  You can eat regular meals one and a half hours before your appointment.  Drink 32 oz. or four large glasses of water.  Do Not go to the washroom until after your exam.